Scientists have proved for the first time that gene therapy is an effective treatment for Parkinson's disease, the progressive disorder of the nervous system which causes tremors, delayed movements and rigidity.

Children with autism may in future be diagnosed by the way they talk and parents may be able to measure their progress by monitoring their speech. Scientists have discovered that the condition has a "unique vocal signature" which could allow affected children to be identified before they show obvious symptoms.

A shortage of vitamin D can lead to Parkinson's disease and mental decline in old age, new research suggests. One 30-year study of 3,000 people revealed a three-fold higher risk of developing Parkinson's in those with low blood levels of vitamin D.